Merge branch 'main' into webfeatures-map-iterator-updates

Author: jugglinmike

package.json

@@ -13,7 +13,7 @@
   "private": true,
   "homepage": "https://github.com/tc39/test262#readme",
   "devDependencies": {
-    "esvu": "^1.2.11",
+    "esvu": "^1.3.0",
     "test262-harness": "^8.0.0"
   },
   "scripts": {

test/built-ins/Temporal/Instant/prototype/toString/timezone-string-datetime.js

@@ -43,20 +43,20 @@ assert.throws(RangeError, () => instance.toString({ timeZone }), "bare date-time
 
 timeZone = "2021-08-19T17:30Z";
 const result1 = instance.toString({ timeZone });
-assert.sameValue(result1.substr(-6), "+00:00", "date-time + Z is UTC time zone");
+assert.sameValue(result1.slice(-6), "+00:00", "date-time + Z is UTC time zone");
 
 timeZone = "2021-08-19T17:30-07:00";
 const result2 = instance.toString({ timeZone });
-assert.sameValue(result2.substr(-6), "-07:00", "date-time + offset is the offset time zone");
+assert.sameValue(result2.slice(-6), "-07:00", "date-time + offset is the offset time zone");
 
 timeZone = "2021-08-19T17:30[UTC]";
 const result3 = instance.toString({ timeZone });
-assert.sameValue(result3.substr(-6), "+00:00", "date-time + IANA annotation is the offset time zone");
+assert.sameValue(result3.slice(-6), "+00:00", "date-time + IANA annotation is the offset time zone");
 
 timeZone = "2021-08-19T17:30Z[UTC]";
 const result4 = instance.toString({ timeZone });
-assert.sameValue(result4.substr(-6), "+00:00", "date-time + Z + IANA annotation is the offset time zone");
+assert.sameValue(result4.slice(-6), "+00:00", "date-time + Z + IANA annotation is the offset time zone");
 
 timeZone = "2021-08-19T17:30-07:00[UTC]";
 const result5 = instance.toString({ timeZone });
-assert.sameValue(result5.substr(-6), "+00:00", "date-time + offset + IANA annotation is the offset time zone");
+assert.sameValue(result5.slice(-6), "+00:00", "date-time + offset + IANA annotation is the offset time zone");

test/built-ins/Temporal/Instant/prototype/toString/timezone-string-leap-second.js

@@ -11,7 +11,7 @@ const instance = new Temporal.Instant(0n);
 let timeZone = "2016-12-31T23:59:60+00:00[UTC]";
 
 const result = instance.toString({ timeZone });
-assert.sameValue(result.substr(-6), "+00:00", "leap second is a valid ISO string for TimeZone");
+assert.sameValue(result.slice(-6), "+00:00", "leap second is a valid ISO string for TimeZone");
 
 timeZone = "2021-08-19T17:30:45.123456789+23:59[+23:59:60]";
 assert.throws(RangeError, () => instance.toString({ timeZone }), "leap second in time zone name not valid");

test/built-ins/Temporal/Instant/prototype/toString/timezone-string-multiple-offsets.js

@@ -11,4 +11,4 @@ const instance = new Temporal.Instant(0n);
 const timeZone = "2021-08-19T17:30:45.123456789-12:12[+01:46]";
 
 const result = instance.toString({ timeZone });
-assert.sameValue(result.substr(-6), "+01:46", "Time zone string determined from bracket name");
+assert.sameValue(result.slice(-6), "+01:46", "Time zone string determined from bracket name");

test/built-ins/Temporal/Instant/prototype/toString/timezone-string.js

@@ -10,7 +10,7 @@ features: [Temporal]
 const instance = new Temporal.Instant(0n);
 
 const result1 = instance.toString({ timeZone: "UTC" });
-assert.sameValue(result1.substr(-6), "+00:00", "Time zone created from string 'UTC'");
+assert.sameValue(result1.slice(-6), "+00:00", "Time zone created from string 'UTC'");
 
 const result2 = instance.toString({ timeZone: "-01:30" });
-assert.sameValue(result2.substr(-6), "-01:30", "Time zone created from string '-01:30'");
+assert.sameValue(result2.slice(-6), "-01:30", "Time zone created from string '-01:30'");

test/built-ins/Temporal/PlainDate/prototype/since/roundingmode-half-boundary.js

@@ -0,0 +1,127 @@
+// Copyright (C) 2026 Rudolph Gottesheim. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaindate.prototype.since
+description: Half rounding modes at the exact 0.5 boundary for years and months
+info: |
+  Tests that all rounding modes correctly break ties at the exact 0.5 boundary
+  in RoundRelativeDuration in the negative direction, for both odd and even
+  integer parts (distinguishing halfEven from other modes). In the negative
+  direction, halfExpand and halfCeil diverge (away from zero vs toward positive
+  infinity).
+
+  Years: dates 2019-01-01 / 2020-07-02 produce a difference of -1 year minus
+  183 days. The year 2020 is a leap year (366 days), so fractional progress =
+  183/366 = 0.5. Dates 2018-01-01 / 2020-07-02 produce -2 years minus 183 days
+  (even integer part).
+
+  Months: dates 2019-01-01 / 2019-02-15 produce -1 month minus 14 days.
+  February 2019 has 28 days, so fractional progress = 14/28 = 0.5.
+  Dates 2018-12-01 / 2019-02-15 produce -2 months minus 14 days (even integer
+  part).
+includes: [temporalHelpers.js]
+features: [Temporal]
+---*/
+
+// --- years ---
+
+// -1.5 years: odd integer part (1) + exact 0.5 fractional progress
+const yearEarlier1 = new Temporal.PlainDate(2019, 1, 1);
+const yearLater = new Temporal.PlainDate(2020, 7, 2);
+
+assert.sameValue(
+  yearEarlier1.until(yearLater).total({ unit: "years", relativeTo: yearEarlier1 }),
+  1.5,
+  "1.5-year duration is on a 0.5 boundary"
+);
+
+for (const mode of ["trunc", "ceil", "halfTrunc", "halfCeil"]) {
+  TemporalHelpers.assertDuration(
+    yearEarlier1.since(yearLater, { smallestUnit: "years", roundingMode: mode }),
+    -1, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    `-1.5 years with ${mode} rounds toward zero`
+  );
+}
+for (const mode of ["floor", "expand", "halfExpand", "halfFloor", "halfEven"]) {
+  TemporalHelpers.assertDuration(
+    yearEarlier1.since(yearLater, { smallestUnit: "years", roundingMode: mode }),
+    -2, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    `-1.5 years with ${mode} rounds away from zero`
+  );
+}
+
+// -2.5 years: even integer part (2) — distinguishes halfEven from halfExpand
+const yearEarlier2 = new Temporal.PlainDate(2018, 1, 1);
+
+assert.sameValue(
+  yearEarlier2.until(yearLater).total({ unit: "years", relativeTo: yearEarlier2 }),
+  2.5,
+  "2.5-year duration is on a 0.5 boundary"
+);
+
+for (const mode of ["trunc", "ceil", "halfTrunc", "halfCeil", "halfEven"]) {
+  TemporalHelpers.assertDuration(
+    yearEarlier2.since(yearLater, { smallestUnit: "years", roundingMode: mode }),
+    -2, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    `-2.5 years with ${mode} rounds toward zero`
+  );
+}
+for (const mode of ["floor", "expand", "halfExpand", "halfFloor"]) {
+  TemporalHelpers.assertDuration(
+    yearEarlier2.since(yearLater, { smallestUnit: "years", roundingMode: mode }),
+    -3, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    `-2.5 years with ${mode} rounds away from zero`
+  );
+}
+
+// --- months ---
+
+// -1.5 months: odd integer part (1) + exact 0.5 fractional progress
+const monthEarlier1 = new Temporal.PlainDate(2019, 1, 1);
+const monthLater = new Temporal.PlainDate(2019, 2, 15);
+
+assert.sameValue(
+  monthEarlier1.until(monthLater).total({ unit: "months", relativeTo: monthEarlier1 }),
+  1.5,
+  "1.5-month duration is on a 0.5 boundary"
+);
+
+for (const mode of ["trunc", "ceil", "halfTrunc", "halfCeil"]) {
+  TemporalHelpers.assertDuration(
+    monthEarlier1.since(monthLater, { smallestUnit: "months", roundingMode: mode }),
+    0, -1, 0, 0, 0, 0, 0, 0, 0, 0,
+    `-1.5 months with ${mode} rounds toward zero`
+  );
+}
+for (const mode of ["floor", "expand", "halfExpand", "halfFloor", "halfEven"]) {
+  TemporalHelpers.assertDuration(
+    monthEarlier1.since(monthLater, { smallestUnit: "months", roundingMode: mode }),
+    0, -2, 0, 0, 0, 0, 0, 0, 0, 0,
+    `-1.5 months with ${mode} rounds away from zero`
+  );
+}
+
+// -2.5 months: even integer part (2) — distinguishes halfEven from halfExpand
+const monthEarlier2 = new Temporal.PlainDate(2018, 12, 1);
+
+assert.sameValue(
+  monthEarlier2.until(monthLater).total({ unit: "months", relativeTo: monthEarlier2 }),
+  2.5,
+  "2.5-month duration is on a 0.5 boundary"
+);
+
+for (const mode of ["trunc", "ceil", "halfTrunc", "halfCeil", "halfEven"]) {
+  TemporalHelpers.assertDuration(
+    monthEarlier2.since(monthLater, { smallestUnit: "months", roundingMode: mode }),
+    0, -2, 0, 0, 0, 0, 0, 0, 0, 0,
+    `-2.5 months with ${mode} rounds toward zero`
+  );
+}
+for (const mode of ["floor", "expand", "halfExpand", "halfFloor"]) {
+  TemporalHelpers.assertDuration(
+    monthEarlier2.since(monthLater, { smallestUnit: "months", roundingMode: mode }),
+    0, -3, 0, 0, 0, 0, 0, 0, 0, 0,
+    `-2.5 months with ${mode} rounds away from zero`
+  );
+}

test/built-ins/Temporal/PlainDate/prototype/until/roundingmode-half-boundary.js

@@ -0,0 +1,123 @@
+// Copyright (C) 2026 Rudolph Gottesheim. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-temporal.plaindate.prototype.until
+description: Half rounding modes at the exact 0.5 boundary for years and months
+info: |
+  Tests that all rounding modes correctly break ties at the exact 0.5 boundary
+  in RoundRelativeDuration, for both odd and even integer parts (distinguishing
+  halfEven from other modes).
+
+  Years: dates 2019-01-01 / 2020-07-02 produce 1 year + 183 days. The year
+  2020 is a leap year (366 days), so fractional progress = 183/366 = 0.5.
+  Dates 2018-01-01 / 2020-07-02 produce 2 years + 183 days (even integer part).
+
+  Months: dates 2019-01-01 / 2019-02-15 produce 1 month + 14 days. February
+  2019 has 28 days, so fractional progress = 14/28 = 0.5. Dates 2018-12-01 /
+  2019-02-15 produce 2 months + 14 days (even integer part).
+includes: [temporalHelpers.js]
+features: [Temporal]
+---*/
+
+// --- years ---
+
+// 1.5 years: odd integer part (1) + exact 0.5 fractional progress
+const yearEarlier1 = new Temporal.PlainDate(2019, 1, 1);
+const yearLater = new Temporal.PlainDate(2020, 7, 2);
+
+assert.sameValue(
+  yearEarlier1.until(yearLater).total({ unit: "years", relativeTo: yearEarlier1 }),
+  1.5,
+  "1.5-year duration is on a 0.5 boundary"
+);
+
+for (const mode of ["trunc", "floor", "halfTrunc", "halfFloor"]) {
+  TemporalHelpers.assertDuration(
+    yearEarlier1.until(yearLater, { smallestUnit: "years", roundingMode: mode }),
+    1, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    `1.5 years with ${mode} rounds down to 1`
+  );
+}
+for (const mode of ["ceil", "expand", "halfExpand", "halfCeil", "halfEven"]) {
+  TemporalHelpers.assertDuration(
+    yearEarlier1.until(yearLater, { smallestUnit: "years", roundingMode: mode }),
+    2, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    `1.5 years with ${mode} rounds up to 2`
+  );
+}
+
+// 2.5 years: even integer part (2) — distinguishes halfEven from halfExpand
+const yearEarlier2 = new Temporal.PlainDate(2018, 1, 1);
+
+assert.sameValue(
+  yearEarlier2.until(yearLater).total({ unit: "years", relativeTo: yearEarlier2 }),
+  2.5,
+  "2.5-year duration is on a 0.5 boundary"
+);
+
+for (const mode of ["trunc", "floor", "halfTrunc", "halfFloor", "halfEven"]) {
+  TemporalHelpers.assertDuration(
+    yearEarlier2.until(yearLater, { smallestUnit: "years", roundingMode: mode }),
+    2, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    `2.5 years with ${mode} rounds down to 2`
+  );
+}
+for (const mode of ["ceil", "expand", "halfExpand", "halfCeil"]) {
+  TemporalHelpers.assertDuration(
+    yearEarlier2.until(yearLater, { smallestUnit: "years", roundingMode: mode }),
+    3, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    `2.5 years with ${mode} rounds up to 3`
+  );
+}
+
+// --- months ---
+
+// 1.5 months: odd integer part (1) + exact 0.5 fractional progress
+const monthEarlier1 = new Temporal.PlainDate(2019, 1, 1);
+const monthLater = new Temporal.PlainDate(2019, 2, 15);
+
+assert.sameValue(
+  monthEarlier1.until(monthLater).total({ unit: "months", relativeTo: monthEarlier1 }),
+  1.5,
+  "1.5-month duration is on a 0.5 boundary"
+);
+
+for (const mode of ["trunc", "floor", "halfTrunc", "halfFloor"]) {
+  TemporalHelpers.assertDuration(
+    monthEarlier1.until(monthLater, { smallestUnit: "months", roundingMode: mode }),
+    0, 1, 0, 0, 0, 0, 0, 0, 0, 0,
+    `1.5 months with ${mode} rounds down to 1`
+  );
+}
+for (const mode of ["ceil", "expand", "halfExpand", "halfCeil", "halfEven"]) {
+  TemporalHelpers.assertDuration(
+    monthEarlier1.until(monthLater, { smallestUnit: "months", roundingMode: mode }),
+    0, 2, 0, 0, 0, 0, 0, 0, 0, 0,
+    `1.5 months with ${mode} rounds up to 2`
+  );
+}
+
+// 2.5 months: even integer part (2) — distinguishes halfEven from halfExpand
+const monthEarlier2 = new Temporal.PlainDate(2018, 12, 1);
+
+assert.sameValue(
+  monthEarlier2.until(monthLater).total({ unit: "months", relativeTo: monthEarlier2 }),
+  2.5,
+  "2.5-month duration is on a 0.5 boundary"
+);
+
+for (const mode of ["trunc", "floor", "halfTrunc", "halfFloor", "halfEven"]) {
+  TemporalHelpers.assertDuration(
+    monthEarlier2.until(monthLater, { smallestUnit: "months", roundingMode: mode }),
+    0, 2, 0, 0, 0, 0, 0, 0, 0, 0,
+    `2.5 months with ${mode} rounds down to 2`
+  );
+}
+for (const mode of ["ceil", "expand", "halfExpand", "halfCeil"]) {
+  TemporalHelpers.assertDuration(
+    monthEarlier2.until(monthLater, { smallestUnit: "months", roundingMode: mode }),
+    0, 3, 0, 0, 0, 0, 0, 0, 0, 0,
+    `2.5 months with ${mode} rounds up to 3`
+  );
+}